It seems the preferred option to do CPL/IR training at one school.
Here is Flybe's requirements:
First officers
Flybe recruit First Officers from a variety of backgrounds and experience levels. Our aim is to recruit candidates with the potential for future command opportunities within the airline.
Newly qualified pilots should have completed either an Integrated or Modular flying course at a recognised Flight Training Organisation (FTO). A minimum of 90% average at ground school stage of training is required. In addition to holding a valid UK CAA or JAR licence and medical on application First Officer candidates should also have completed a Multi Crew Co-operation course. Modular candidates should have completed training at a single FTO, not including basic PPL training or ATPL theory study and examination.
Good luck with the training.